Hebrew Voices #7 – Orthodox Jew Who Sights the New Moon

Orthodox Jew Who Sights the New Moon, Hebrew, hoffman, calendar, software Orthodox Jew, Jew, Judaism, New Moon, Crescent, sighting, Chemistry, Scientist, Science, Rosh Chodesh, Maimonodes, Rosh Hashanah, Yom Teruah, Archeo-astronomy, SanhedrinIn this episode of Hebrew Voices, Orthodox Jew Who Sights the New Moon, Nehemia Gordon delves deep into Rosh Chodesh with Dr. Roy Hoffman, founder of the Israeli New Moon Society. From Moses, to Hillel the Younger, to Maimonides, Hoffman explains Orthodox perspectives related to sightings of the new moon.  Hoffman also introduces LunaCal, a free software application he developed to calculate when and where the new moon is most lightly to be visible.

Dr. Hoffman explains intricacies of new moon terminology and calculations, the difference between a sighting calendar and a calculated calendar, the role of the Sanhedrin, the creation of calendars through the centuries, and how new moon sightings relate to the practice of Jews in the Diaspora observing holidays for two days instead of one.

Though Gordon and Hoffman hold differing views on when to observe Rosh Chodesh today, they close on common ground—looking forward to the time when the calendar is perfected under the reign of the King Messiah.

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Show Notes:

Dr. Roy Hoffman was born in 1963 in London, UK. As a child, he had a strong interest in science and technology and benefited from the beginnings of the microcomputer revolution. He went on to study Chemistry at University and because of his attraction to mathematics and computing went into physical chemistry for his PhD. Seeking to experience a more spiritual relationship with his faith, he applied for work in Israel, and accepted a post-doc position at Hebrew University. He is the founder of the Israeli New Moon Society. In Jerusalem, he met Channa who became his wife. Today, they have five children: Jonathan, Rina, Akiva, Sarah and Na'ama.

LunaCal Software

  • Elchabar says:

    Do you think the astronomical or dark moon is when the Hebrew month is supposed to start?

  • trish392016 says:

    My interest always lie in the Jewish custom and understanding do hearing about Dr Roy Hoffman and where he was born outside of Yisrael yet returned there and get marry there now sighted the moon just like the biblical times …this really touch me very deep.

    Thanks to you too Nemehia’ you were recommended to me by Allan Horvath who said you do have full knowledge on biblical truth and I find that out to be so my self as I had always been listening to you

  • Rocky Jackson says:

    OK what or where am I missing ( atem) atem atem in Leviticus 23?

    I can’t find it three times let along once!

    Was it simply misquoted ?

    • Actually it says Otam, but the raabis interpret it as Atem 3 times using their Midrashic prerogative. I talk about this in my book “Shattering the Conspiracy of Silence”. It’s actually quite important for understanding the history of the vowels.

  • Mary says:

    Great interview-stayed on topic-and got to the roots without rabbit holes!
    Thank you!

  • One question do shabbats are according to the moon cycles? My husband and I keep the shabbats this way, are going to be this week on Thursday? We have studied for the last 6 years that are according to the moon cycles Psalms 104:19

    • Dori says:

      There are very few who follow the lunar calendar, with determining the Shabbats by the moon. I do not believe Nehemia is in agreement with the whole concept. Like you we have been noticing that the moon does change its phases every 7 days. As to your question as far as the U.S., our 1st quarter moon ? was seen in yesterday’s sky pointing to today, Friday, as the 7th day AFTER our new moon day sighting. Next Friday will be ?, then ?, then ?…

  • Geoff Robinson says:

    That was a great interview on a good topic. Thanks for letting Dr. Roy Hoffman share the history and essentials so well. I appreciate how you do your interviews. I think it is wonderful that you wanted him to share his opinion, not just the parts that agree with your position. I missed a couple of your first interviews of this series, but I look forward to going back and listen to the ones I missed.
    (Fort Collins, CO USA)

  • Ferdinand Blom says:

    Nice interview Nehemia. I enjoyed picking up some new historical details.

  • Michael says:

    Appreciate you being led Nehemia to interview this person. Such great information and a heavy topic that is needed for the life of a TorahWalker. Keep them coming may Yehovah bless you this day.

  • Our hearts leaps for great joy for hearing such! The New Moon observations coming more open and public in Israel within the Orthodox Jews as well in addition to the Karaites and Messianic / Hebrew Roots believers. HalleluYeHoVah! Shabbat Shalom from Finland…

  • Achi, WOW I give you much credit for being able to hold your tongue. So much info. gives me a headache ! I wish we could watch your discussion with Rav. Hoffman it is very interesting to something that really is an important topic, as a meshichi it excites me to hear that the orthodox are expecting Moshiach to come soon as you are also. And you know what I believe I guess, as the joke goes, we’ll have to ask Him if it’s His 1st time or has He been here before. lol ! Excellent work Achi. Until we hear “Baruch ha ba B’shem Yehova” take care and Shalom, Shalom !!!

  • Shawn Lichaa says:

    Nehemia, this was wonderful.

  • Dori says:

    Interesting talk, but how were they able to decide the new moon during Moses time? We are in California and we have observed that some months we are ahead of Israel and sometimes behind. Studying the moon has become quite fascinating.

    • Shawn Lichaa says:

      Hi Dori,

      In the Rabbinic Tradition it is absolutely necessary for the new moon to be the new moon of Israel.

      It is entirely possible for the new moon to be seen at a different time than the moon in Israel. (It should always be the case, as I understand it, that if the moon is seen in Israel it will necessarily be seen in CA – atmosphere permitting.)

      BTW, the majority historical Karaite Jewish view is that the local moon matters – not the Israel moon. (I am a Karaite and I myself go back and forth about this issue.)

      I am actually undertaking a study about the moon and the calendar currently.

      • Dori says:

        Thank you for sharing. We have been doing our best to observe (see) the new moon for 3 years. Yes our local time, by the moon, can say we are a day a head of Israel and other moons are a day behind. We were putting the lunar sabbath to the test and find Yehovah’s time clock in the sky amazingly accurate. The moons that are difficult to spot can throw things off, but once the 1st quarter is seen it works like clock work. No way could our culture today observe what was once probably in place. As retirees we enjoy looking up and wondering how our ancestors lived without a printed calendar.